This invention relates to an improved method of immunization and, particularly, to an improved method for inducing antibody formation in a host mammal. The invention is also concerned with an immunogenic implant for carrying out the said method. In addition, this invention is concerned with the production of specific immunoglobulins derived therefrom.
It is known that the introduction of antigens by injection into a mammal promotes the formation of antibodies; and this knowledge is the basis of most immunization techniques. The antibodies so produced are proteinaceous substances (immunoglobulins) derived from plasma cell lines and are characterized by classification according to internationally accepted classes for immunoglobulin. Each such class may be further characterized by the antigen against which it is directed.
An antigen broadly may be defined as a substance that can induce an immune response (Alfred Nisonoff, "Introduction to Molecular Immunology," Sinauer Associates Inc., 1982). More strictly, an antigen is a substance containing one or more antigenic determinants, wherein an antigenic determinant is a molecule or portion of a molecule capable of recognizing and binding firmly to the combining site of an antibody. Most naturally-occuring antigens are proteins, although non-proteinaceous material may be antigenic. Also synthetic antigens have been made. A virus particle or a single bacterium normally will contain many different kinds of antigens.
As used herein the term antigen is intended to mean a molecule which will induce a specific immune response, i.e. which will induce the formation of antibodies when introduced into a mammalian host.
Various methods are known in the art for inducing immune response by the injection of antigens.
For example, Stahli et al, Journal of Immunological Methods, Vol. 32 (1980) pages 297-304, dealing with the production of monoclonal antibodies against soluble antigens, describe the maintenance of high concentrations of circulating antigen, for successfully inducing plasma cell formation, by repeated injections.
Nisonoff, "Introduction to Molecular Immunology", 1982, discloses that subcutaneous or intramuscular injection of an emulsion of an antigen and an adjuvant permits prolonged slow release of the antigen and tends to increase the production of antibodies. Suitable adjuvants are alum or complete Freund's adjuvant (a water-in-oil emulsion containing killed mycobacteria and a detergent).
Axen et al, in U. S. Pat. No. Re. 29474, also disclose repeated subcutaneous injections of antigenic protein with complete Freund's adjuvant to produce antibodies in animals.
Wands et al, U. S. Pat. No. 4,271,145, disclose a process for preparing an antibody to a human viral hepatitis antigen which involves an intraperitoneal injection followed by an intravenous injection of the hepatitis antigen. Wands et al also disclose a composition comprising a hybrid continuous cell line for producing an antibody.
East German Patent No. 146,687 to Bundschuh, issued Feb. 25, 1981, discloses the intraperitoneal or intravenous injection of antigen into a host, (i.e. any antibody-producing animal) for the preparation of an antiserum.
Olovnikov et al, Chemical Abstracts, Vol. 64, 1966, Column 16457, disclose protein-cellulose immunosolvents on which protein antigens are chemically bonded to an insoluble carrier. The preparation is subsequently injected into the host and results in prolonged antibody production.
Freund, Annual Review of Microbiology, Vol. 1, 1947, pages 291-308, discloses various adjuvants used in conjunction with antigens to enhance immunization. Administration is by injection.
Gonzalez et al, Compt. Rend. Soc. Biol., Vol. 106, 1931, pages 1006-1008, and Ramon et al, Compt. Rend. Soc. Biol., Vol. 118, 1935, pages 108-111, also disclose the use of adjuvants and show administration only by injection.
Heretofore the procedure recognized for inducing the formation of antibodies was the administration of antigen by injection. Surprisingly, it has now been found that antibodies may be induced in a mammal by the introduction of an implant comprising a predetermined antigen impregnated on a suitable substrate, and that such implantation will promote and facilitate the production of higher titers (greater concentration) of antibodies.